Non-functional liquid polymers are known in the art. They are prepared by the emulsion polymerization utilizing emulsifiers, chain transfer agents, initiators, coagulants, and the like. Also utilized are mercaptans which function as chain terminators. The use of a mercaptan, however, causes the non-functional liquid polymers to be turbid and also to have a strong sulfur-like odor.
U.S. Pat. No. 3,426,006 (Nutzel et al., Feb. 4, 1969) relates to a process for producing substantially colorless telomers, homopolymer and copolymer of conjugated diolefins comprising utilizing as a polymerization catalyst a compound of the general formula ##STR1## wherein Me is an alkali metal; X is phosphorus, tin or lead; R is a hydrocarbon; and y is 2-3; the Me-X bond being a homopolymer bond.
Canadian Patent No. 834,303 relates to interpolymerizing a butadiene (for example, butadiene, 2,3-dimethyl butadiene, isoprene or chlorobutadiene) , and ethylenically unsaturated acid (for example acrylic acid, methacrylic acid, allylic acid, fumaric acid, or itaconic acid) and an acrylonitrile (acrylonitrile or methacrylonitrile). The polymerization is carried out using 0. 1 to 0. 5 parts of an azo initiator (for example, azobisisobutyronitrile) in aqueous emulsion in the presence of 2.5 to 5 parts of a cationic emulsifier (for example, cetyldimethylbenzyl ammonium chloride) and 5 to 12 parts of a mercaptan modifier (for example, n-dodecyl mercaptan) for 100 parts of monomers. The interpolymerization is short stopped (for example, by 0.15 to 2 parts of hydroxyl ammonium sulfate) at 40 to 80 percent, preferably 65 to 75 percent, conversion to form an emulsion of liquid rubber.